Field of Invention
The present invention relates to a speaker, and more particularly to a diaphragm and suspension edge having elastic ribs, and a speaker.
Description of Related Art
A conventional acoustic device, such as a speaker, generally comprises a speaker frame, a vibration diaphragm supported by the speaker frame, a voice coil coupled at the vibration diaphragm, and a magnetic coil unit magnetically inducing with voice coil for driving the vibration diaphragm to vibrate for sound reproduction. In particular, the vibration diaphragm is mounted at an opening of the speaker frame, wherein when the voice coil is magnetically induced to reciprocatingly move, the vibration diaphragm is driven to vibrate correspondingly. However, the vibration direction of the vibration diaphragm is uncontrollable, such that the vibration diaphragm cannot reproduce good sound quality. In order to achieve better sound quality, the vibration diaphragm should only be reciprocatingly moved one direction with even amplitude. For example, when the vibration diaphragm is placed horizontally, the vibration diaphragm should only be reciprocatingly moved in a vertical (up-and-down) direction while the upward displacement of the vibration diaphragm should be the same as the downward displacement of the vibration diaphragm.
An elastic-wave member, also known as center supporting frame, usually made of cotton and synthetic fibers, it is generally disposed in conventional audio devices to control vibration directions of the diaphragm. The elastic-wave member has an inner side coupling with the voice coil and an outer side coupling with the speaker frame. The elastic-wave member is supported to provide a stable spring force, thereby maintaining the voice coil and the diaphragm to return to their initial positions. For example, when the diaphragm moves to its topside position, the elastic force of the elastic-wave member will pull the diaphragm to return to its initial position.
Since the elastic-wave member and the diaphragm are made of different materials, the elastic-wave member and the diaphragm have different elastic forces. In particular, the diaphragm has a greater elastic force than the elastic-wave member, so that when the diaphragm is moved to its topside position, the elastic-wave member pulls the diaphragm to return to its initial position. In other words, when the diaphragm returns to its initial position, there will not be a downward movement of the diaphragm. The elastic-wave member will only pull down the diaphragm to the initial position from the topside position. In addition, since the elastic-wave member has a larger elastic force, the downward pulling movement of the diaphragm is faster than the upward movement of the diaphragm. As a result, the diaphragm reciprocated movement is not uniform in velocity. Since the elastic-wave member makes the voice coil to move in a nonlinear manner. Once the voice coil is not aligned its central axis, the voice coil may scratch and touch the inside of the speaker. The protective coating of the voice coil will gradually be damaged. More importantly, the amplitude of the diaphragm is limited by the large elastic force of the elastic-wave member. Especially for a sound device reproducing a low-frequency sounds, the diaphragm requires a relatively large amplitude to vibrate reciprocally. In other words, the elastic-wave member will affect the reproduction of low frequency sounds.
Because of the elastic-wave member, the voice coil and the speaker frame have a greater distance, and in a conventional speaker, the magnetic coil system and the diaphragm also have a large distance. Thus, a larger space is formed among the diaphragm, the voice coil, the magnetic coil system and the speaker frame. In other words, in the conventional speaker, the voice coil can deviate from its axial displacement direction to produce a greater shaking from side to side and displacements, causing the impure sound.
In addition, in the conventional speaker, the voice coil is connected to the diaphragm and the elastic-wave member, thus the voice coil moves reciprocally under the impact of a magnetic force of the magnetic coil unit, the elastic-wave member can play a role of restricting on the voice coil, so that when the diaphragm is needed to reach a larger amplitude, the pulling force of the elastic-wave member needs to take into account, so that a magnetic force of a magnet of the magnetic coil unit need to be big enough to ensure the diaphragm to overcome the pulling force of the elastic-wave member and has a desired amplitude.
For many small sized devices with audio arrangement such as flat-panel TVs, mobile phones and laptop, these audio arrangement need to be flat and thin, so that the small sized devices can maintain compact product designs and unique shapes. As the elastic-wave member must be supported be the speaker away from the diaphragm, the size of the speaker must be big enough, thereby providing enough space for the movement of the centering supporting frame.